Thanks for filing the issue!

Unable to reproduce the issue on reported chrome version 66.0.3359.170 using Mac 10.12.6, Mac 10.13.1 and Mac 10.13.3 with the below mentioned steps.
1. Launched chrome
2. Navigated to https://codepen.io/nicoladelazzari/pen/YLLKJM
We have neither observed any flicker of content on animation nor any square shape. Attaching the screen cast for reference.

@Reporter: Could you please have a look at the screen cast and let us know if we have missed anything in the process. Any further inputs from your end may be helpful.

Deleted: 842065.mp4 2.8 MB

	842065.mp4 2.8 MB View Download

Hi, I edit the pen to repeat the animation in infinite mode.
Fin in attachment a screen cast with the issue
Thank you

Deleted: cz-codepen.mov 2.2 MB

	cz-codepen.mov 2.2 MB View Download

I made an update on codepen
https://codepen.io/nicoladelazzari/pen/YLLKJM

Are you able to replicate the issue?

Any updates?

Able to reproduce(...with the updated test file given in comment#4) the issue on reported chrome version 66.0.3359.170 and on the latest canary 68.0.3437.2 using Mac 10.13.1, Ubuntu 14.04 and Windows !0. 
As the issue is seen from M60(60.0.3112.0) considering it as Non-Regression, hence removing Needs-Bisect label. Please add the label back if required.

Thanks!

Hi trchen@, could you please take a look at the bug? According to the bisect result, the regression seems to be caused by your change. Thanks!
  https://chromium.googlesource.com/chromium/src/+log/80c88c5f2e38809780dad854b33447d8041eec61..fc25706df1a4e7ee35bcd3623a33a30ea837199e

I can only repro this with --disable-gpu. It looks like the tile anti-aliasing is not done correctly in software renderer. Any tiled clip path that doesn't align to device pixel will result in tile seams.

Here is a minimal repro: http://output.jsbin.com/zufapidawi/quiet

Reassign to viz renderer team for further investigation.

Changing the component tag.

 Issue 843546  has been merged into this issue.

Any updates?

Any updates about this?

Ping

:(